Hydrangea arborescens plant named ‘NCHA2’

ABSTRACT

A new and distinct  Hydrangea  cultivar named ‘NCHA2’ is disclosed, characterized by large, mop-head inflorescences with prevalent sterile flowers and large, dark pink sepals. Plant habit is compact, and plants are triploid. The new variety is a  Hydrangea  normally produced as an outdoor garden or container plant.

Latin name of the genus and species: The Latin name of the novel plant variety disclosed herein is Hydrangea arborescens.

Variety denomination: The seedling of Hydrangea arborescens disclosed herein has been given the varietal denomination ‘NCHA2’.

BACKGROUND OF THE INVENTION

The present invention comprises a new and distinct hydrangea cultivar hereinafter referred to by the cultivar name ‘NCHA2’. This new hydrangea was developed through a breeding program at North Carolina State University, Mills River, N.C. ‘NCHA2’ was selected from a population of seedlings that resulted from a cross between the pollen parent, Hydrangea arborescens H2008-143-001 (unpatented) and the seed parent Hydrangea arborescens H2009-067-039 (unpatented). See FIG. 1 for a complete pedigree. The first asexual propagation of ‘NCHA2’ was carried out in July 2012 by rooting stem cuttings at the North Carolina State University, Mountain Horticultural Crops Research Station, Mills River, N.C. and has been asexually reproduced repeatedly by vegetative cuttings over a three year period. ‘NCHA2’ roots readily from softwood cuttings treated with a basal dip of 2,500-5,000 ppm indole butyric acid (potassium salt) in water. ‘NCHA2’ has been found to retain its distinctive characteristics through successive asexual propagations.

SUMMARY OF THE INVENTION

The following are the unique combination of characteristics of this new cultivar when grown under standard horticultural practices at North Carolina State University, Mountain Horticultural Crops Research Station, Mills River, N.C.

-   -   1. Large, mop-head inflorescences (i.e., a hortensia flower         form) with prevalent sterile flowers and large, dark pink         sepals.     -   2. Triploid cytotype.     -   3. Compact form.

COMPARISON WITH PARENT VARIETIES

‘NCHA2’ is similar to the seed parent in most horticultural characteristics, however, the new variety differs in the following:

-   -   1. The new variety has a darker and stronger red-purple sterile         sepal color.     -   2. The new variety has as different ploidy level, 3.6 pg,         compared to 5.2 pg of the seed parent.

‘NCHA2’ is similar to the pollen in most horticultural characteristics, however, the new variety differs in the following:

-   -   1. The new variety has a different red-purple sterile sepal         color.     -   2. The new variety has a different ploidy level, 3.6 pg,         compared to 2.7 pg of the pollen parent.

COMPARISON WITH COMMERCIAL CULTIVARS

Table 1 shows distinguishing characteristics between ‘NCHA2’ and other commercially available cultivars of Hydrangea arborescens. Hydrangea arborescens ‘NCHA2’ has a unique combination of traits including a mophead inflorescence, large pink sepals, a compact form, and a triploid cytotype.

TABLE 1 Comparison to other cultivars. Taxa H. arborescens H. arborescens H. arborescens ‘NCHA1’ ‘NCHA2’ ‘NCHA3’ (U.S. Plant Pat. (U.S. application (U.S. application Trait No. 20,765) No. 14/545,787) No. 14/545,795) Ploidy level Diploid Triploid Triploid (genome size, pg) (2.7 pg) (3.9 pg) (3.8 pg) Growth habit Rounded Rounded Rounded Height and width 100 cm × 100 cm 80 cm × 80 cm 60 cm × 60 cm Stem internode 5 to 15 cm Avg. 7 cm Avg. 6 cm length (typical range: (typical range: 3 to 10 cm) 3 to 8 cm) Flowers per inflorescence Fertile Approx. 600 Approx. 150 Approx. 150 Sterile Approx. 600 Approx. 300 Approx. 300 Corymb 8-20 cm Avg. 14 cm Avg. 12 cm diameter Sepal color Above Red-Purple Red-Purple Red-Purple (ranges from (65A to 67C) (60C) fading to 68D/C to fading to Red- Red-Purple N66D/N66C) Purple (65C) (70C) Below Red-Purple Red-Purple Red-Purple (ranges from (63B) (60A) 68D/C to N66D/N66C) Sepal Length 0.5-0.7 cm Avg. 1.2 cm Avg. 1.0 cm Width 0.3-0.5 cm Avg. 1.0 cm Avg. 0.7 cm Taxa H. arborescens H. arborescens ‘NCHA4’ ‘PIIHA-I’ (U.S. application (U.S. Plant Pat. Trait No. 14/545,796) No. 21,227) Ploidy level Triploid Unknown (genome size, pg) (3.8 pg) Growth habit Rounded Upright, spreading Height and width 80 cm × 80 cm 90 cm × 90 cm Stem internode Avg. 7 cm About 6 cm length (typical range: 3 to 10 cm) Flowers per inflorescence Fertile Approx. 200 Approx. 75 Sterile Approx. 400 Approx. 300 Corymb diameter Avg. 20 cm Avg. 12.5 cm Sepal color Above Red-Purple Close to Red- (63D to 65B) Purple (58A) Below Red-Purple Close to Red- (63A) Purple (63A) Sepal Length Avg. 1.0 cm 0.7 cm Width Avg. 0.7 cm 0.5 cm

BRIEF DESCRIPTION OF THE DRAWINGS

This new Hydrangea is illustrated by the accompanying photographs which show the plant's pedigree, form, foliage and inflorescences. Photographs were taken of 2-year-old plants. The colors shown are as true as can be reasonably obtained by conventional photographic procedures. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description, which accurately describe the colors of the new hydrangea.

FIG. 1 Shows the pedigree of ‘NCHA2’.

FIG. 2 Shows the inflorescences with pink sepals.

FIG. 3 Shows the mature habit.

DETAILED BOTANICAL DESCRIPTION

The following is a detailed description of the botanical characteristics of the new and distinct hydrangea variety plant known by the denomination ‘NCHA2’. The detailed description was taken on a three-year-old field-grown plant in Mills River, N.C. in 2014. All colors cited herein refer to The Royal Horticultural Society Colour Chart (The Royal Horticultural Society (R.H.S.), London, 2001 Edition). Where specific dimensions, sizes, colors, and other characteristics are given, it is to be understood that such characteristics are approximations or averages set forth as accurately as practicable.

Technical Description of the Variety

-   Classification:     -   -   Botanical name.—Hydrangea arborescens ‘NCHA2’.         -   Common name.—Smooth Hydrangea. -   Plant description:     -   -   Growth habit.—Upright, rounded, non-climbing.         -   Height (from top of soil including inflorescences).—About 80             cm.         -   Width (including inflorescences).—About 80 cm. -   Shoot and stem:     -   -   Shoot length.—60 cm (typical range: 40 to 80 cm).         -   Shoot diameter.—0.5 cm (typical range: 0.3 to 1.0 cm).         -   Internode length.—7 cm (typical range: 3 to 10 cm).         -   Shoot texture.—Pubescent.         -   Shoot color.—Yellow-Green (146C).         -   Mature stem texture (from prior year).—Glabrous.         -   Mature stem color (from prior year).—Grey-Brown (199D).         -   Fasciation.—Not present.         -   Lenticels.—Not present. -   Branching habit: Freely branching with as many as 100 or more     terminal shoots. -   Foliage:     -   -   Type.—Simple.         -   Persistence.—Deciduous.         -   Arrangement.—Opposite.         -   Shape.—Broadly ovate. Not lobed.         -   Apex.—Acuminate. 2 to 5 mm average length.         -   Base.—Rounded.         -   Venation.—Pinnate, opposite to subopposite.         -   Vein color.—Upper: Yellow-Green (148B). Lower: Yellow-Green             (148D).         -   Margins.—Dentate to serrate.         -   Texture.—Upper surface: Glabrous. Lower surface: Slightly             pubescent.         -   Emerging leaves.—Color: Upper and lower: Yellow-Green             (146B).         -   Mature leaves during growing season.—Color: Upper: Green             (139A). Lower: Yellow-Green (146B). Length of lamina: Avg. 8             cm (typical range: 6 to 9 cm). Width: Avg. 6 cm (typical             range: 3 to 8 cm).         -   Variegation.—None.         -   Leaf attachment.—Petiolate.         -   Petiole.—Length: Avg. 3 cm (typical range: 1 to 4 cm).             Diameter: Avg. 0.2 cm (typical range: 0.15 to 0.25 cm).             Color: Brown (200C to 200D). -   Inflorescence:     -   -   Description.—Fertile (approximately 300) and sterile             (approximately 150) flowers arranged on individual             hemispherical or dome-shaped terminal, compound corymbs.             Fertile flowers moderately conspicuous.         -   Flowering season.—Late May to early August in Mills River,             N.C.         -   Corymb.—Diameter: Average 14 cm (typical range: 12 to 15             cm). Height: Average 7 cm (typical range: 5 to 8 cm).             Quantity: Often 100 or more corymbs per plant over the             flowering season. Longevity: Showy for approximately 4             weeks.         -   Sterile flowers.—Petals, pistils and stamens are greatly             reduced (<0.5 mm). Buds: Shape: Round. Diameter: 0.2 cm.             Color: Red-Purple (63A). Sepals: Number: 2 to 4. Length:             Avg. 1.2 cm (typical range: 0.9 to 1.3 cm). Width: Avg. 1.0             cm (typical range: 0.8 to 1.2 cm). Shape: Oval. Apex:             Rounded. Base: Cuneate. Margin: Entire. Texture: Glabrous             upper and lower surfaces. Color: Upper: Red-Purple (65A to             67C)) fading to Red-Purple (65C). Lower: Red-Purple (63B).         -   Fertile flowers.—Sepals and petals are greatly reduced (<0.5             mm). Buds: Shape: Round. Diameter: 0.2 cm. Color: Red-Purple             (62C to 62D). Width: 0.2 cm. Height: 0.2 cm. -   Reproductive organs:     -   -   Gynoecium.—Pistil number: 2, fused. Pistil color: White             (155B). Pistil length: 0.2 cm. Stigma shape: Blunt. Stigma             diameter: 0.06 cm. Style length: 0.1 cm (typical range: 0.95             to 1.09 cm). Ovary shape: Rounded. Ovary diameter: 0.1 cm.             Ovary color: Near RHS Yellow-Green 145B.         -   Androecium.—Stamen number: 10. Anther: Shape: Rounded,             fusiform. Length: 0.06 cm. Color: White (158D). Filament:             Length: Avg. 0.2 cm (typical range: 0.1 to 0.4 cm). Color:             White (155B). Amount of pollen: Scarce.

OTHER CHARACTERISTICS

-   Fruit/seed set: Seeds are minute, dust-like. Color not accurately     measured with R.H.S. chart. -   Disease and insect resistance: No significant disease or insect     pests have been observed. -   Cold hardiness: At least USDA zone 6b; testing has not been     completed in colder zones. -   Genome size: Flow cytometry was conducted to determine DNA content     which is directly correlated with ploidy among closely related taxa.     Holoploid, 2C DNA content was determined on newly expanded leaf     tissue. Nuclei were extracted, stained with     4′,6-Diamidino-2-phenylindole (DAPI), and analyzed (minimum of 5,000     nuclei per sample) using a flow cytometer (PA-I, Partec, Münster,     Germany). Pisum sativum L. ‘Ctirad’, with a known genome size of     8.75 pg was used as an internal standard. 2C DNA content for ‘NCHA2’     was 3.9 pg, approximately 1.5 times the DNA content of a diploid     (e.g., ‘NCHA1’), and consistent with being a triploid as would be     expected from an interploid cross between diploid and tetraploid     parents (see Table 1). 

What is claimed is:
 1. A new and distinct cultivar of Hydrangea arborescens named ‘NCHA2’ as illustrated and described herein. 